How to use Code First generated context class with WCF DataServices?
I could use POCO template generated context class inherited from ObjectContext in conjunction with WCF DataServices with following configurations in WCF Service :
public class WcfDataService : DataService< NorthwindEntities >
{
public static void InitializeService(DataServiceConfiguration config)
{
config.SetEntitySetAccessRule("*", EntitySetRights.AllRead);
config.SetServiceOperationAccessRule("*", ServiceOperationRights.All);
config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;
}
protected override NorthwindEntities CreateDataSource()
{
var ctx = new NorthwindEntities();
ctx.ContextOptions.ProxyCreationEnabled = false;
return ctx;
}
}
However, context class which CTP5 generated is not possible in that same way because it does not inherit from ObjectContext, instead it inherits from DbContext.
How to solve this problem?
Thanks in advance
You can accomplish this by accessing the ObjectContext through the IObjectContextAdapter interface.
protected override NorthwindEntities CreateDataSource()
{
var ctx = new NorthwindEntities();
((IObjectContextAdapter)ctx).ObjectContext
.ContextOptions.ProxyCreationEnabled = false;
return ctx;
}
Related
I am using a .net standard class library to implement Entity Framework core on an existing ASP.NET MVC web application.
I am injecting the data context into the classes I am using, but I also need a static implementation for some specific method calls. The obvious issue here is that in the static context, I don't have an injected data context. so i did the following.
What is the correct way to do this?
I am using a Ninject Module in the library to map dependencies to the kernel in the web project.
namespace AppealTrack.Logic.Classes
{
using System;
using System.Collections.Generic;
using System.Linq;
using Common.Entities;
using Data;
using Interfaces;
using Microsoft.EntityFrameworkCore;
public class LookupLogic : ILookupLogic, IDisposable
{
private readonly AppealTrackDataContext _context;
public LookupLogic(AppealTrackDataContext context)
{
_context = context;
}
public List<County> GetCountries(string state)
{
var list = _context.Countries.Where(x => state == null || x.State == state).Distinct().AsNoTracking().ToList();
return list;
}
public void Dispose()
{
}
}
public static class LookupLogicStatic
{
public static List<County> GetCountries(string state)
{
// this is the part that I don't think is correct:
using (var logic = new LookupLogic(new AppealTrackDataContext()))
{
var list = logic.GetCountries(state);
return list;
}
}
}
}
If you require a static GetCountries method, then there is not much you can do... you would need to manage the scope of DbContext for that method as static constructor does not take any arguments. Your LookupLogic does not have to be Disposable though (it can be if you want).
If you require a static method, then you don't have to add a new static class, you can add the static method to LookupLogic:
public class LookupLogic : ILookupLogic
{
private readonly AppealTrackDataContext _context;
public LookupLogic(AppealTrackDataContext context)
{
_context = context;
}
public List<Country> GetCountries(string state)
{
return GetCountries(_context, state);
}
public static List<Country> GetCountriesStatic(string state)
{
using (var dbContext = new AppealTrackDataContext())
{
return GetCountries(dbContext, state);
}
}
private static List<Country> GetCountries(AppealTrackDataContext dbContext, string state)
{
return dbContext.Countries.Where(x => state == null || x.State == state).Distinct().AsNoTracking().ToList();
}
}
I'm trying to create a viewmodel provider factory and I'm little bit lost. I've already added the required Nuget packages and my view models extend the AndroidViewModel type. Now, I'd like to create a factory that would use autofac to create the required view models from the OnCreate activitie's method. The creation call looks like this:
_viewModel = (ViewModelProviders.Of(this, _viewModelFactory)
.Get(Java.Lang.Class.FromType(typeof(MainActivityViewModel))) as JavaObjectWrapper<MainActivityViewModel>)
.Object;
Now, the factory:
public class ViewModelFactory : ViewModelProvider.AndroidViewModelFactory {
public ViewModelFactory(Application application) : base(application) {
}
public override Object Create(Class modelClass) {
// TODO: any way to get the .NET type that was passed here?
return base.Create(modelClass);
}
}
Can I retrieve the .NET type (MainActivityViewModel) from the Class instance that is passed into the Create method call (the type would be required to resolve it from the autofac container)? If there is, how can I do that?
Thanks.
This is how I do this with Unity, but this pattern can be used for passing anything through the ViewModel constructor:
The ViewModel itself
public class HomeViewModel : ViewModel
{
IUnityContainer _unityContainer;
public HomeViewModel(IUnityContainer unityContainer)
{
_unityContainer = unityContainer;
}
}
The HomeViewModelFactory (Default constructor required)
public class HomeViewModelFactory : Java.Lang.Object, ViewModelProvider.IFactory
{
IUnityContainer _unityContainer;
public HomeViewModelFactory()
{
}
public HomeViewModelFactory(IUnityContainer unityContainer)
{
_unityContainer = unityContainer;
}
public Java.Lang.Object Create(Class p0)
{
return _unityContainer.Resolve<HomeViewModel>();
}
}
Usage in Fragment
public override void OnActivityCreated(Bundle savedInstanceState)
{
base.OnActivityCreated(savedInstanceState);
var homeViewModelFactory = _unityContainer.Resolve<HomeViewModelFactory>();
_homeViewModel = ViewModelProviders.Of(this, homeViewModelFactory).Get(Java.Lang.Class.FromType(typeof(HomeViewModel))) as HomeViewModel;
}
I am working on adding Entity Framework to our web app, asp.net MVC 5, but I am having a hardtime saving changes and adding to the database. I set up UnitOfWork with a generic BaseRepository, and I have tried a few things attempting to get this to work. first, I thought I could inject, with AutoFac, my repo in UnitOfWork like so
public UnitOfWork(IServiceItem serviceItem
, ITechServiceItem techServiceItem
, ITechnicianTime technicianTime
, ISproc sproc
, IRepairOrder repairOrder
, ICustomer customer
, IRepairOrderStatus repairOrderStatus
, IRepairOrderUnit repairOrderUnit
, IFiles files
, IPartInventory partInventory
, IRepairOrderItems repairOrderItems
)
{
RepairOrderItems = repairOrderItems;
PartInventory = partInventory;
Files = files;
RepairOrderUnit = repairOrderUnit;
RepairOrderStatus = repairOrderStatus;
RepairOrder = repairOrder;
Customer = customer;
Sproc = sproc;
ServiceItem = serviceItem;
TechServiceItem = techServiceItem;
TechnicianTime = technicianTime;
}
and my BaseRepo is like
public class BaseRepository<TEntity> : IRepository<TEntity> where TEntity : class
{
protected DataDbContext _db;
public class BaseRepository<TEntity> : IRepository<TEntity> where TEntity : class
{
protected DataDbContext _db;
internal void GetData()
{
if (_db == null)
{
string accountNumber = HttpContext.Current.User.Identity.GetCompanyAccountNumber();
var connectionToken = ConfigurationManager.AppSettings["LoginSplitToken"];
_db = new DataDbContext(ConfigurationManager.ConnectionStrings["NameOfConnString"].ConnectionString.Replace(connectionToken, accountNumber));
}
}
public TEntity Get(int id)
{
return _db.Set<TEntity>().Find(id);
}
public IEnumerable<TEntity> GetAll()
{
return _db.Set<TEntity>().ToList();
}
public IEnumerable<TEntity> Find(Expression<Func<TEntity, bool>> predicate)
{
return _db.Set<TEntity>().Where(predicate);
}
public void Add(TEntity entity)
{
_db.Set<TEntity>().Add(entity);
}
public void AddRange(IEnumerable<TEntity> entities)
{
_db.Set<TEntity>().AddRange(entities);
}
public void Remove(TEntity entity)
{
_db.Set<TEntity>().Remove(entity);
}
public void RemoveRange(IEnumerable<TEntity> entities)
{
_db.Set<TEntity>().RemoveRange(entities);
}
public int CompleteData()
{
return _db.SaveChanges();
}
public TEntity Get(int id)
{
return _db.Set<TEntity>().Find(id);
}
public IEnumerable<TEntity> GetAll()
{
return _db.Set<TEntity>().ToList();
}
public IEnumerable<TEntity> Find(Expression<Func<TEntity, bool>> predicate)
{
return _db.Set<TEntity>().Where(predicate);
}
public void Add(TEntity entity)
{
_db.Set<TEntity>().Add(entity);
}
public void AddRange(IEnumerable<TEntity> entities)
{
_db.Set<TEntity>().AddRange(entities);
}
public void Remove(TEntity entity)
{
_db.Set<TEntity>().Remove(entity);
}
public void RemoveRange(IEnumerable<TEntity> entities)
{
_db.Set<TEntity>().RemoveRange(entities);
}
public int CompleteData()
{
return _db.SaveChanges();
}
}
and my StartUp.Configuration
public void Configuration(IAppBuilder app)
{
var builder = new ContainerBuilder();
HttpConfiguration config = GlobalConfiguration.Configuration;
// REGISTER DEPENDENCIES
builder.RegisterType<EverLogicDbContext>().AsSelf().InstancePerRequest();
builder.RegisterType<ApplicationUserManager>().AsSelf().InstancePerRequest();
builder.RegisterType<ApplicationSignInManager>().AsSelf().InstancePerRequest();
builder.Register(c => HttpContext.Current.GetOwinContext().Authentication).InstancePerRequest();
builder.Register(c => HttpContext.Current.User).InstancePerRequest();
builder.Register(c => app.GetDataProtectionProvider()).InstancePerRequest();
builder.RegisterType<ApplicationUserStore>().As<IUserStore<EverLogicMamber, int>>()
.WithParameter(new TypedParameter(typeof(ISecurityOfWork), new SecurityOfWork(new SecurityDbContext())))
.InstancePerRequest();
//Database
builder.RegisterType<UnitOfWork>().As<IUnitOfWork>().InstancePerRequest();
builder.RegisterType<SecurityOfWork>().As<ISecurityOfWork>().InstancePerRequest();
//Service
builder.RegisterType<TechnicianTimeService>().As<ITechnicianTimeService>().InstancePerRequest();
builder.RegisterType<PartService>().As<IPartService>().InstancePerRequest();
builder.RegisterType<TechServiceItemService>().As<ITechServiceItemService>().InstancePerRequest();
//Repo
builder.RegisterType<Company>().As<ICompany>().InstancePerRequest();
builder.RegisterType<Views>().As<IViews>().InstancePerRequest();
builder.RegisterType<RepairOrderItems>().As<IRepairOrderItems>().InstancePerRequest();
builder.RegisterType<PartInventory>().As<IPartInventory>().InstancePerRequest();
builder.RegisterType<Files>().As<IFiles>().InstancePerRequest();
builder.RegisterType<TechDashboardService>().As<ITechDashboardService>().InstancePerRequest();
builder.RegisterType<RepairOrderUnit>().As<IRepairOrderUnit>().InstancePerRequest();
builder.RegisterType<RepairOrderStatus>().As<IRepairOrderStatus>().InstancePerRequest();
builder.RegisterType<Customer>().As<ICustomer>().InstancePerRequest();
builder.RegisterType<ServiceItem>().As<IServiceItem>().InstancePerRequest();
builder.RegisterType<RepairOrder>().As<IRepairOrder>().InstancePerRequest();
builder.RegisterType<Sproc>().As<ISproc>().InstancePerRequest();
builder.RegisterType<TechServiceItem>().As<ITechServiceItem>().InstancePerRequest();
builder.RegisterType<TechnicianTime>().As<ITechnicianTime>().InstancePerRequest();
// REGISTER CONTROLLERS SO DEPENDENCIES ARE CONSTRUCTOR INJECTED
builder.RegisterControllers(typeof(MvcApplication).Assembly);
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
builder.RegisterWebApiFilterProvider(config);
builder.RegisterWebApiModelBinderProvider();
var container = builder.Build();
// REPLACE THE MVC DEPENDENCY RESOLVER WITH AUTOFAC
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
app.UseAutofacMiddleware(container);
app.UseAutofacMvc();
config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
ConfigureAuth(app);
}
But with this set up, the database does not update or add new entitys.
Then i tryed removing Dependcy injection from UnitOfWork and set UnitOfWork up like
protected DataDbContext _db;
public UnitOfWork(DataDbContext context)
{
GetData();
RepairOrderItems = new RepairOrderItems(_db);
PartInventory = new PartInventory(_db);
Files = new Files(_db);
RepairOrderUnit = new RepairOrderUnit(_db);
RepairOrderStatus = new RepairOrderStatus(_db);
RepairOrder = new RepairOrder(_db);
Customer = new Customer(_db);
Sproc = new Sproc(_db);
ServiceItem = new ServiceItem(_db);
TechServiceItem = new TechServiceItem(_db);
TechnicianTime = new TechnicianTime(_db);
}
internal void GetData()
{
if (_db == null)
{
string accountNumber = HttpContext.Current.User.Identity.GetCompanyAccountNumber();
var connectionToken = ConfigurationManager.AppSettings["LoginSplitToken"];
_db = new DataDbContext(ConfigurationManager.ConnectionStrings["NameOfConnString"].ConnectionString.Replace(connectionToken, accountNumber));
}
}
and moving SaveChanges from the BaseRepo to UnitOfWork, but still nothing is saving or adding to the database.
What am i missing????
TL;DR the problem is that all your repositories are using separate, independent DbContexts, so the DbContext injected into your UnitOfWork has no pending changes when you call SaveChanges on it, so that's why you aren't seeing any change to the database.
In order for the Unit of Work to function correctly, your UnitOfWork class, and all the repository classes which your code needs to perform data persistence, must all share the same DbContext instance. In your code, it's clear that each repository has a factory method to create it's own, independent DbContext instance.
Remove the GetData() factory method from your BaseRepository class, and instead, require an instance of your EverLogicDbContext instance to injected to the constructor of BaseRepository by AutoFac. This will require that all your Repository subclasses also need to have a constructor accepting this same EverLogicDbContext.
As per your last edit, the UnitOfWork class must accept the same, shared EverLogicDbContext that the repositories use. Since you've tagged with asp.net-mvc then RequestPerInstance lifetime scope is correct for your scenario.
Your UnitOfWork class needs to control the SaveChanges(Async) method, so remove the CompleteData method from the BaseRepository class.
As you already seem to have done, the DbContext needs to be registered InstancePerRequest:
builder.RegisterType<EverLogicDbContext>().AsSelf().InstancePerRequest();
If all this is tied together correctly:
AutoFac will create an instance of your concrete DbContext the first time it is needed during processing of each Request.
All Repositories will then share the same DbContext instance for the lifetime of the Request, and the DbContext will track interim changes made by your services.
The UnitOfWork injected into your main "business logic" (e.g. Controller, or Orchestrator / Handler) will then be able to Commit the actions taken by simply calling SaveChangesAsync on the shared DbContext. This will all happen under a single database connection, so will be a lightweight transaction.
As per other comments above, IMO Entity Framework is a already high level framework with transactional support built-in, so there's little point in over-engineering a "UnitOfWork" pattern if all the ACID activity will be conducted against the same Database (and can be wrapped into the same DbContext).
I am working on an ASP.Net Core MVC Web application.
My Solution contains 2 projects:
One for the application and
A second project, dedicated to unit tests (XUnit).
I have added a reference to the application project in the Tests project.
What I want to do now is to write a class in the XUnit Tests project which will communicate with the database through entity framework.
What I was doing in my application project was to access to my DbContext class through constructor dependency injection.
But I cannot do this in my tests project, because I have no Startup.cs file. In this file I can declare which services will be available.
So what can I do to get a reference to an instance of my DbContext in the test class?
You can implement your own service provider to resolve DbContext.
public class DbFixture
{
public DbFixture()
{
var serviceCollection = new ServiceCollection();
serviceCollection
.AddDbContext<SomeContext>(options => options.UseSqlServer("connection string"),
ServiceLifetime.Transient);
ServiceProvider = serviceCollection.BuildServiceProvider();
}
public ServiceProvider ServiceProvider { get; private set; }
}
public class UnitTest1 : IClassFixture<DbFixture>
{
private ServiceProvider _serviceProvider;
public UnitTest1(DbFixture fixture)
{
_serviceProvider = fixture.ServiceProvider;
}
[Fact]
public void Test1()
{
using (var context = _serviceProvider.GetService<SomeContext>())
{
}
}
}
But bear in your mind using EF inside a unit test is not a good idea and it's better to mock DbContext.
The Anatomy of Good Unit Testing
You can use Xunit.DependencyInjection
For unit tests you need to mock your context.
There is a great nuget package for mocking that is called Moq.
Some help to get you started:
public ClassName : IDisposable
{
private SomeClassRepository _repository;
private Mock<DbSet<SomeClass>> _mockSomeClass;
public ClassName()
{
_mockSomeClass = new Mock<DbSet<SomeClass>>();
var mockContext = new Mock<IApplicationDbContext>();
mockContext.SetupGet(c => c.SomeClass).Returns(_mockSomeClass.Object);
_repository = new SomeClassRepository(mockContext.Object);
}
public void Dispose()
{
// Anything you need to dispose
}
[Fact]
public void SomeClassTest()
{
var someClass = new SomeClass() { // Initilize object };
_mockSomeClass.SetSource(new[] { someClass });
var result = _repository.GetSomethingFromRepo( ... );
// Assert the result
}
}
For integration tests you do the same thing but the setup is:
_context = new ApplicationDbContext();
Make sure that your TestClass inherits from IDisposable (TestClass : IDisposable) so that you can dispose the context after each test.
https://xunit.github.io/docs/shared-context
You can to use package Microsoft.EntityFrameworkCore.InMemory
var _dbContextOptions = new DbContextOptionsBuilder<DbContext>().UseInMemoryDatabase(Guid.NewGuid().ToString()).Options;
And then
var context = new DbContext(_dbContextOptions);
I am very new to Ninject and am trying Ninject 2 with MVC and Linq. I have a SqlProductRepository class and all I want to know is what's the best way of passing the connectionstring in the constructor if I am injecting the Repository object in the controller.
public class SqlProductRepository:IProductRepository
{
private Table<Product> productsTable;
public SqlProductRepository(string connectionString)
{
productsTable = (new DataContext(connectionString)).GetTable<Product>();
}
public IQueryable<Product> Products
{
get { return productsTable; }
}
}
This is my ProductController class where I am injecting the Repository:
public class ProductsController : Controller
{
private int pageSize = 4;
public int PageSize { get { return pageSize; } set { pageSize = value; } }
IProductRepository _productsRepository;
[Inject]
public ProductsController(IProductRepository productRepository)
{
_productsRepository = productRepository;
}
public ViewResult List(int page)
{
return View(_productsRepository.Products
.Skip((page - 1) * pageSize)
.Take(pageSize)
.ToList()
);
}
}
Can somebody please guide me regarding this?
You can set it up in your binding
_kernel.Bind<IProductRepository>()
.To<SqlProductRepository>()
.WithConstructorArgument("connectionString",yourConnectionString );
You're doing:
new DataContext(connectionString)
in your code - this is the very newing and binding to classes you're trying to push out of your code by using a DI container. At the very least, consider adding an IConnectionStringSelector interface or something like that. You dont want to have 20 Bind calls for 20 repositories - you want a higher level abstraction than that.
I'd suggest the best solution is that you should be demanding either an IDataContext or an IDataContextFactory in the constructor instead and letting that worry about it.
You could supply the connection string as a constructor argument when binding the SqlProductRepository to the IProductRepository interface.
public class LinqToSqlModule : NinjectModule
{
public override void Load()
{
Bind<IProductRepository>().To<SqlProductRepository>()
.WithConstructorArgument(connectionString, "connectionstring");
}
}
I would suggest a slightly different approach. First of all, you might want to create a binding for the DataContext class in the kernel. You could do so by using a provider class to create your DataContext passing the connection string as an argument to its constructor. Then you bind the DataContext to the DataContextProvider.
public class DataContextProvider : Provider<DataContext>
{
protected override DataContext CreateInstance(IContext context)
{
string connectionString = "connectionstring";
return new DataContext(connectionString);
}
}
public class LinqToSqlModule : NinjectModule
{
public override void Load()
{
Bind<DataContext>().ToProvider<DataContextProvider>();
Bind<IProductRepository>().To<SqlProductRepository>();
}
}
Next modify the constructor of SqlProductRepository class to accept a DataContext object instead.
public class SqlProductRepository : IProductRepository
{
private readonly DataContext context;
public ProductRepository(DataContext context)
{
this.context = context;
}
public IQueryable<Product> Products
{
get { return context.GetTable<Product>(); }
}
}
By the way you don't have to decorate your constructor with the Inject attribute. Ninject will select the constructor with the most parameters by default.
Please refer below code snap:
//Bind the default connection string
public void BindDataContext()
{
ConstructorArgument parameter = new ConstructorArgument("connectionString", "[Config Value]");
Bind<DataContext>().ToSelf().InRequestScope().WithParameter(parameter);
}
//Re-Bind the connection string (in case of multi-tenant architecture)
public void ReBindDataContext(string cn)
{
ConstructorArgument parameter = new ConstructorArgument("connectionString", cn);
Rebind<DataContext>().ToSelf().InRequestScope().WithParameter(parameter);
}
For more information, please visit below link
MVC3, Ninject and Ninject.MVC3 problem